An inkjet printing system may include a printhead, an ink supply which supplies liquid ink to the printhead, and an electronic controller which controls the printhead. The printhead ejects drops of ink through a plurality of nozzles or orifices and toward a print medium, such as a sheet of paper, so as to print onto the print medium. Typically, the orifices are arranged in one or more columns or arrays such that properly sequenced ejection of ink from the orifices causes characters or other images to be printed upon the print medium as the printhead and the print medium are moved relative to each other.
The printhead, also referred to as a printhead die, communicates with the electronic controller via an electrical circuit. In some implementations, the electrical circuit is a flexible circuit secured to a body, such as a printer cartridge, that also supports the printhead. Properly securing the electrical circuit to the body is desirable for reliable printhead operation, as non-uniform or uneven securing of the flexible electrical circuit makes the circuit more susceptible to damage and potentially leads to decreased performance during various printer functions, such as during capping and wiping of the printhead.
Various methods can be used to inspect the connection between the flexible electrical circuit and the supporting body. For example, the strength of the bond between the flexible electrical circuit and the supporting body can be evaluated by measuring the force required to peel the flexible circuit off the supporting body. However, such testing is destructive so it can only be used on a sample of parts, and the peel force does not indicate uniformity of the connection. In another method, a shim is inserted between the flexible circuit and the supporting body to confirm the extent of the connection. However, this method only checks the perimeter of the connection area, and does not indicate how well the elements are secured to each other. Visual inspection for gaps between edges of the flexible circuit and the supporting body may also be conducted, but such visual inspection does not provide any empirical evidence regarding the uniformity or strength of the connection.
For this and other reasons, there is a need for the present invention.